Question

我想要进行登录过程，登录后我有listview显示所有用户来自数据库，每行有编辑和删除按钮，并在listview后添加按钮，所以我写了所有的代码，但是当用户登录时，应用程序关闭下这是代码：的 DBHandler.java：

element.style.prop = 'prop'

MainActivitiy

   package com.mehrandashti.letmelearn.zabansara;

/**
 * Created by Welcome on 2017/2/14.
 */


import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.util.ArrayList;
import java.util.List;

public class DBHandler extends SQLiteOpenHelper {

    // Database Version
    private static final int DATABASE_VERSION = 1;
    // Database Name
    private static final String DATABASE_User = "UserInfo";
    // Contacts table name
    private static final String TABLE_UserS = "Users";
    // Users Table Columns names
    private static final String KEY_ID = "id";
    private static final String KEY_User = "User";
    private static final String KEY_PASS = "pass";
    public DBHandler(Context context) {
        super(context, DATABASE_User, null, DATABASE_VERSION);
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_UserS + "("
        + KEY_ID + " INTEGER PRIMARY KEY," + KEY_User + " TEXT"
        + KEY_PASS + " TEXT" + ")";
        db.execSQL(CREATE_CONTACTS_TABLE);
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_UserS);
// Creating tables again
        onCreate(db);
    }
    // Adding new User
    public void addUser(User User) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_ID,User.getId());
        values.put(KEY_User, User.getUser()); // User Name
        values.put(KEY_PASS, User.getPass()); // User Phone Number

// Inserting Row
        db.insert(TABLE_UserS, null, values);
        db.close(); // Closing database connection
    }
    // Getting one User
    public User getUser(int id) {
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.query(TABLE_UserS, new String[]{KEY_ID,
                KEY_User, KEY_PASS}, KEY_ID + "=?",
        new String[]{String.valueOf(id)}, null, null, null, null);
        if (cursor != null)
            cursor.moveToFirst();

        User contact = new User(Integer.parseInt(cursor.getString(0)),
                cursor.getString(1), cursor.getString(2));
// return User
        return contact;
    }
    // Getting All Users
    public List<User> getAllUsers() {
        List<User> UserList = new ArrayList<User>();
// Select All Query
        String selectQuery = "SELECT * FROM " + TABLE_UserS;

        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);

// looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                User user = new User();
                user.setId(Integer.parseInt(cursor.getString(0)));
                user.setUser(cursor.getString(1));
                user.setPass(cursor.getString(2));
// Adding contact to list
                UserList.add(user);
            } while (cursor.moveToNext());
        }

// return contact list
        return UserList;
    }
    // Getting Users Count
    public int getUsersCount() {
        String countQuery = "SELECT * FROM " + TABLE_UserS;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery, null);
        cursor.close();

// return count
        return cursor.getCount();
    }
    // Updating a User
    public int updateUser(User User) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_User, User.getUser());
        values.put(KEY_PASS, User.getPass());

// updating row
        return db.update(TABLE_UserS, values, KEY_ID + " = ?",
        new String[]{String.valueOf(User.getId())});
    }

    // Deleting a User
    public void deleteUser(User User) {
        SQLiteDatabase db = this.getWritableDatabase();
        db.delete(TABLE_UserS, KEY_ID + " ="+User.getId(),
        new String[] { String.valueOf(User.getId()) });
        db.close();
    }
}

网页

package com.mehrandashti.letmelearn.zabansara;

import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AlertDialog;

import android.os.Bundle;


import java.util.List;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity implements OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        Button buttonEnter = (Button) findViewById(R.id.button);
        buttonEnter.setOnClickListener(this);



    }




    @Override
    public void onClick(View v) {
        DBHandler db = new DBHandler(this);


        EditText user = (EditText) findViewById(R.id.editText);
        EditText pass = (EditText) findViewById(R.id.editText4);

      String s1=user.getText().toString();
      String  s2=pass.getText().toString();

        List<User> Users = db.getAllUsers();
        for (User User : Users) {

            if (s1.equals(User.getUser()) && s2.equals(User.getPass())) {

                Intent launchNewIntent = new Intent(MainActivity.this,Page.class);
                startActivityForResult(launchNewIntent, 0);
                break;
            }
            else
            {
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setTitle("نام کاربری یا رمز ورود اشتباه می باشد ");
                builder.setMessage("لطفا در وارد نمودن آنها دقت کنید");
                builder.setPositiveButton("ok", null);
                AlertDialog dialog = builder.show();
                break;

            }

        }

    }
}

MyCustomAdapter

package com.mehrandashti.letmelearn.zabansara;

import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AlertDialog;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.FilterQueryProvider;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

import java.util.ArrayList;

public class Page extends ActionBarActivity implements View.OnClickListener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.page);
        //generate list
        ArrayList<String> list = new ArrayList<String>();
        list.add("item1");
        list.add("item2");

        //instantiate custom adapter
        MyCustomAdapter adapter = new MyCustomAdapter(list, this);

        //handle listview and assign adapter
        ListView lView = (ListView)findViewById(R.id.listview1);
        lView.setAdapter(adapter);

    }
    DBHandler db=new DBHandler(this);
    @Override
    public void onClick(View v) {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
        alertDialog.setTitle("Add New User");
        final EditText inputuser = new EditText(this);
        final EditText inputpass = new EditText(this);
        alertDialog.setView(inputuser);
        alertDialog.setView(inputpass);
        alertDialog.setPositiveButton("Yes Option", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                //What ever you want to do with the value
                String uss = inputuser.getText().toString();
                String pss = inputpass.getText().toString();
               db.addUser(new User(uss,pss));

            }
        });

        alertDialog.setNegativeButton("No Option", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                // what ever you want to do with No option.
                dialog.cancel();
            }
        });

        alertDialog.show();

    }
}
**User**
package com.mehrandashti.letmelearn.zabansara;


 public class User {
     private int id;
     private String user;
     private String pass;

     public User(){}
public User( String user, String pass){
    this.user = user;
    this.pass = pass;
}

     public User(int id, String user, String pass) {
         this.id = id;
         this.user = user;
         this.pass = pass;
     }
public User(int id)
{
    this.id=id;
}
     public void setId(int id) {
         this.id = id;
     }

     public void setUser(String user) {
         this.user = user;
     }
     public void setPass(String pass) {
         this.pass = pass;
     }
     public int getId() {
         return id;
     }
     public String getPass() {
         return pass;
     }
     public String getUser() {
         return user;
     }
 }

page.xml

package com.mehrandashti.letmelearn.zabansara;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.TextView;

import com.mehrandashti.letmelearn.zabansara.R;

import java.util.ArrayList;

public class MyCustomAdapter extends BaseAdapter implements ListAdapter {
    private ArrayList<String> list = new ArrayList<String>();
    private Context context;

    DBHandler db=new DBHandler(context);

    public MyCustomAdapter(ArrayList<String> list, Context context) {
        this.list = list;
        this.context = context;
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int pos) {
        return list.get(pos);
    }

    @Override
    public long getItemId(int pos) {
        return 0;
        //just return 0 if your list items do not have an Id variable.
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        View view = convertView;
        if (view == null) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = inflater.inflate(R.layout.user, null);
        }

        //Handle TextView and display string from your list
        TextView listItemText = (TextView)view.findViewById(R.id.textView2);
        listItemText.setText(list.get(position));
        TextView list1ItemText = (TextView)view.findViewById(R.id.editText4);
        list1ItemText.setText(list.get(position));

        //Handle buttons and add onClickListeners
        Button deleteBtn = (Button)view.findViewById(R.id.delete);
        Button editBtn = (Button)view.findViewById(R.id.edit);

        deleteBtn.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                //do something
                User us=new User();
                db.deleteUser(new User(position));
                list.remove(position); //or some other task
                notifyDataSetChanged();
            }
        });
        editBtn.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                //do something
                notifyDataSetChanged();
            }
        });

        return view;
    }
}

user.xml

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="444dp"
        android:id="@+id/listview1" />

    <Button
        android:text="Add User"
        android:layout_width="199dp"

        android:layout_height="match_parent"
        android:id="@+id/button2"
        android:layout_marginLeft="80dp" />
</LinearLayout>

android列表视图，带2个按钮

0 个答案: